Sometimes Apple gets significantly early delivery of products from Intel before other manufacturers get delivery. I wonder if that'll happen in this case, which could mean an even earlier release of the mac pro update.
Perhaps. Apple buying the initial lots of chips could explain the large delay from from the virtually identically bloomsfield chips.
The only real difference between the two is that a Xeon will work in a multi-socket computer. The current Core i7 will only work in a single-socket motherboard.
The Gainestown "Xeon" (we won't know the real name until Intel announces it) is not a "better" chip - it just has the ability to run on a dual-socket motherboard, and it has a much, much higher price.
Nobody is asking for a quad Core i7 mini-tower as a "stopgap" - there's a huge hole in Apple's desktop product line.
Not only that, but especially with this release the bloomfield Core i7 (also Xeon 3500 with ECC support) and the Xeon 5500 (Gainestown) are identical with the exception of the quick path link. Likewise the current x58 desktop motherboard (Tylersburg SP) is identical to the new server/workstation board (Tylserburg DP) with the exception of a second quick path link. Same memory, same socket.